I know the filter vs. non-filter debate will never be resolved; that's why I decided to test my own gear and see for myself so I could make my own decision. In case it's of any help to others trying to figure out whether a UV filter is worth it merely for "protection," here are my results.

These were all taken with a 5Dii and a Canon 70-200mm f/2.8 (non-IS) on a tripod and a 10-second timer to reduce vibrations, etc. Shutter speed 1/60 of a second to account for any cycling in the compact fluorescent lights in my house. Aperture 2.8 because I wanted to test my lens' sharpness wide-open while I was at it. I think most variables were adequately controlled to give a good side-by-side comparison.

Images were taken at four different focal lengths (70mm, 100mm, 135mm and 200mm) and are 100% crops. Those taken without a filter are on the left, those taken with a cheap ($20) UV filter are on the right.

70mm


100mm


135mm


200mm



To my eye the most noticeable difference is that the images with the filter are darker, which I guess is to be expected. I won't comment on what else I see in terms of difference just yet as I'd be interested to hear what others think first.

RobsonF wrote:
...I'd be interested to hear what others think first.


Don't use the filter, unless you have to.

Seems to be a noticeable hit in contrast. Of course you're going to see a far bigger and nastier hit the moment you get light coming into the lens, even good filters will knock you there which is why even after spending on the best, I stopped using a UV.

I don't understand why people don't take the money they spend on high quality filters, and get an insurance policy instead. Most of them are dirt cheap, say $50-$100 a year, and even if you get a $200/year policy that covers completely crazy $$ of gear and all kind of situations with no deductible, you're still getting way more protection than any filter can offer for your money...

An insurance policy covers EVERYTHING (if you get a good one)...

While a $60 filter prevents you from smashing the front element,...maybe....and even then its probably damaged from dropping it anyways, and now you have a $1500 paperweight...or you could pay $60 a year, for all your equipment, and get it replaced instead of being stuck with dropped lenses....

I understand the fact that its a yearly charge instead of a one time, but hell, just think of it as adding a new lens and getting a new filter for it every year...




...It absolutely blows my mind that people spend money on filters, when they could get a $10,000 insurance policy instead for the same amount of money

Crap on=crap out. Nice test, thanks for taking the time to post.
Other negative effects could include flare/ghosting and AF issues.
This has been discussed ad nauseum since I've been here, the proof
is out there. If it makes you sleep better, go for it...just don't believe
there's no optical downside to your paranoia. One of my favorite sights
at an event: guy spendin' $2000 on a 70-200, adds a UV filter and shoots
with his hood reversed.

RobsonF,

Great test that shows the importance of using quality filters. I've done comparison tests with B&W and Nikon filters and my results were vastly different than yours. The filters did make test-images slightly darker, but there was absolutely NO difference in sharpness/detail after pixel-peeping the bejesus out of the shots. Just for curiosity, which brand filter did you use?

Thanks,
Nicholas
www.copperhillimages.com

KibblesNbitz wrote:
...It absolutely blows my mind that people spend money on filters, when they could get a $10,000 insurance policy instead for the same amount of money

I don't normally use filters. OTOH, when shooting in challenging environments with blowing sand and/or salt water spray, I use them to protect the front elements of my lenses. An insurance policy wouldn't help for this.

jcolwell wrote:
KibblesNbitz wrote:
...It absolutely blows my mind that people spend money on filters, when they could get a $10,000 insurance policy instead for the same amount of money

I don't normally use filters. OTOH, when shooting in challenging environments with blowing sand and/or salt water spray, I use them to protect the front elements of my lenses. An insurance policy wouldn't help for this.

No, it certainly does not get the shot. I like to use filters around volcanoes, at the ocean, or in Yellowstone.

EBH

Yep. After doing this test I've parked the UV filter in my bag for use in extreme situations only. I was thinking of maybe trying out some higher-quality UV filters but the point about buying insurance instead makes a lot of sense.

The filter I used, incidentally, is made by Fidelity Electronics. Just a basic, $20, 77mm UV filter.

The test is valid but is also necessarily limited. One of the greatest risks with using cheap (uncoated or poorly coated) filters is that they can reflect light back into the lens to cause or worsen ghosting and/or veiling flare, and this effect is most noticeable when the scene has areas of highlights in otherwise areas. This test does not show that. Even if it did, the effect is also somewhat dependent on which lens is used and whether it has a modern optical deign that minimizes reflections from the sensor back onto the sensor. There are many variables.

Back in the old film days the film did not reflect as much light back into the lens as a modern digital sensor does. Also, the film was more sensitive to UV than digital sensors are. That's why we started out years ago with the philosophy that filters were more helpful than harmful.

- Alan

An interesting debate and one I have read before.

Here's a related question: I just bought a Nikon 24-70 f/2.8 and plan to use it to shoot a divisional rock climbing event (indoors) this coming weekend. The environment is simply awash with chalk dust and I am worried about the effect on my lens, especially without a filter. Reading the above, this sounds like one of the "extreme settings" justifying their use. With that in mind, what filter would you recommend without breaking the bank?

Thanks for your thoughts.

http://www.bhphotovideo.com/c/product/121298-REG/Nikon_2482_77mm_Clear_NC_Glass.html

Nicholas
www.copperhillimages.com

thr1961 wrote:
An interesting debate and one I have read before.

Here's a related question: I just bought a Nikon 24-70 f/2.8 and plan to use it to shoot a divisional rock climbing event (indoors) this coming weekend. The environment is simply awash with chalk dust and I am worried about the effect on my lens, especially without a filter. Reading the above, this sounds like one of the "extreme settings" justifying their use. With that in mind, what filter would you recommend without breaking the bank?

Thanks for your thoughts.
Tim, you might look into Marumi Super Lens Protectors...I use 'em for my Rodeo remotes. Reasonably priced, high quality.

this exercise has been done about 10-15 times in the last 8 years here.

chalk dust is about the hardness of what they use in lenspens for cleaning lens surfaces. that's not the issue. the issue is how often do you have to clean under those conditions and what else besides chalk might get onto the lens. indoors in a climbing gym? it's not remotely extreme.

Herb...

thr1961 wrote:
Here's a related question: I just bought a Nikon 24-70 f/2.8 and plan to use it to shoot a divisional rock climbing event (indoors) this coming weekend. The environment is simply awash with chalk dust and I am worried about the effect on my lens, especially without a filter. Reading the above, this sounds like one of the "extreme settings" justifying their use. With that in mind, what filter would you recommend without breaking the bank?

HerbChong wrote:
chalk dust is about the hardness of what they use in lenspens for cleaning lens surfaces. that's not the issue. the issue is how often do you have to clean under those conditions and what else besides chalk might get onto the lens. indoors in a climbing gym? it's not remotely extreme.

Herb...

thr1961 wrote:
Here's a related question: I just bought a Nikon 24-70 f/2.8 and plan to use it to shoot a divisional rock climbing event (indoors) this coming weekend. The environment is simply awash with chalk dust and I am worried about the effect on my lens, especially without a filter. Reading the above, this sounds like one of the "extreme settings" justifying their use. With that in mind, what filter would you recommend without breaking the bank?


I agree with Herb. Not an extreme example of environmental considerations.
Usually wind is the determining factor for me. Whether its ocean spray, desert sand or chalk dust, the wind is what drives those elements onto the lens surfaces and inside a non-sealed interior.

For me one of the main reasons to use a UV filter is:
It filters UV light! duh.
I don't have any experience with cheap ones, but a good one can actually add contrast by eliminating some of the UV spectrum. This is especially noticeable outside in very bright daylight. This is also when you will notice a considerable difference between a cheap filter and one of those pricey, multi-coated filters.
I may not know the exact science of how the UV filtering aspect works, but that's my experience anyway.
If you're just using the filter for protection a clear filter would be better, because it doesn't have as much "effect" on the image.

Doesn't the sensor's filter block UV? I'd like to see some examples of how any UV filter improves an image taken with a digital camera.

dcains wrote:
Doesn't the sensor's filter block UV? I'd like to see some examples of how any UV filter improves an image taken with a digital camera.

You're probably right.
I need to do a test. Frankly, I haven't used a UV filter in awhile. Whether there's a benefit or not, usually I just can't be bothered.

dcains wrote:
Doesn't the sensor's filter block UV? I'd like to see some examples of how any UV filter improves an image taken with a digital camera.

If the UV has no purpose, wouldn't it be better to get a clear filter?